I don't know how new Tangled is, but there is a fairly mature github alternative being built on Nostr:

https://gitworkshop.dev/

The basic idea is that you can put your repository on multiple GRASP-compatible nostr relays (GRASP is a sub-protocol that glues nostr and git together), so even if one server goes down you can transparently sync using the others. This means in effect 100% uptime if you choose reliable servers, as well as cryptographically-signed repositories, activity, issues, etc.